The invention pertains to a method for providing manufacturing-related data in the large-scale production of manufactured objects, in particular, automobiles.
In the large-scale production of automobiles, it is common practice to assign a so-called accompanying card to each automobile. This card accompanies the automobile while it passes through manufacturing sections, e.g., while the automobile passes through different preassembly and assembly sections, and is assigned to this automobile. Complaints of the workers who are active in these manufacturing sections are registered on this accompanying card in the various manufacturing sections. These complaints may, for example, pertain to defects of the components or groups of components used in the large-scale production. For example, a reference on the accompanying card may indicate that a certain component, e.g., an air filter, is damaged or contains another defect, e.g., the air filter is soiled. This also applies to groups of components, e.g., auxiliary heating systems or air conditioning systems. The accompanying card may also contain a reference to missing components if a component required in a certain manufacturing section is unavailable.
After passing through the various manufacturing sections of the large-scale production, the accompanying card is removed from the automobile such that a list of complaints pertaining to this automobile is available and the required subsequent work can be planned and initiated based on the references on the accompanying card, e.g., the replacement of defective components, the installation of missing components or other subsequent improvements. After the subsequent work is carried out, the accompanying card is archived for a certain duration.
One disadvantage of this known method can be seen in the fact that the registration of complaints on the accompanying card is complicated, laborious and susceptible to errors since the accompanying card is quite extensive due to the large quantity of components used in large-scale production, in particular, of automobiles. For example, this accompanying card may consist of several DIN A4 sheets such that the registration of the respective complaint is relatively difficult, in particular, under time pressure.
Another disadvantage of this known method is that the complaints of the workers which are registered on the accompanying card are not available for planning the subsequent work if the accompanying card is used otherwise, e.g., if a worker is currently registering complaints on the accompanying card. This is the reason why certain check points are provided during the manufacturing process in accordance with this known method. The accompanying card is removed at these check points and the required subsequent work can be planned in accordance with the complaints of the workers registered on the accompanying card. This means that the manufacturing-related data for planning the subsequent work are only available at these check points. This is not practical and complicates the planning of subsequent work.
A method for providing manufacturing-related data in the large-scale production of automobiles is known from xe2x80x9cPatent Abstracts of Japan,xe2x80x9d No. 61108079 and from DE 41 13 556 A1 which refers to the previously mentioned publication. In this method, a movable communication device that accompanies the automobile during the manufacturing process is assigned to each automobile.
A similar method is known from GB 2 279 775 A.
The present invention is based on the objective of disclosing a method of the initially mentioned type which does not exhibit the disadvantages of the known method, i.e., a method, in which the collecting and providing of manufacturing-related data is simplified.
Instead of using an accompanying card of paper, the invention proposes a data collecting device that is assigned to the manufactured object, e.g., an automobile, analogous to the accompanying card in the known method described above. Workers are able to enter manufacturing-related data in the form of complaints into the data collecting device in the various manufacturing sections if a defect is detected in the respective manufacturing section. The data may, for example, be input by means of a keyboard or a touchscreen of the data collecting device.
The invention also proposes that the data be at least partially transmitted from the data collecting device to at least one central device during manufacturing. This may, for example, be realized by means of a radio transmission.
This means that the manufacturing-related data are centrally available in the central device and can be used for planning the required subsequent work.
Since the data are, according to the invention, already available in the central device during the manufacturing process, it is no longer necessary to wait until a manufactured object has passed through the entire manufacturing process. The planning of subsequent work consequently may take place while the manufactured object is still located in the manufacturing process. This significantly simplifies the planning of subsequent work and makes it possible to save time and lower costs.
The method according to the invention is particularly suitable for the large-scale production of automobiles. However, it may also be used in the large-scale production of any other manufactured object, e.g., in the manufacture of electronic devices. Consequently, the method according to the invention can be universally utilized.
The data collecting device can have a simple design, e.g., in the form of a simple hand-held computer. Since computers of this type are durable and robust, they can be used over an extended period of time. This has advantageous effects with respect to cost. Another advantage of the method according to the invention can be seen in the fact that the manufacturing-related data can be stored and archived in the central device in the form of electronic data. Consequently, all processes associated with the archiving of the accompanying card in the known method can be executed in a program-controlled fashion. This results in additional time savings and consequently cost reductions.
According to one practical additional development of the method according to the invention, the data collecting device is assigned to the respective manufactured object at the beginning of a first predetermined manufacturing section, with the data collecting device remaining assigned to the respective manufactured object up to a second predetermined manufacturing section. Due to this measure, a fixed allocation of the data collecting device to the respective manufactured object is ensured between the first and the second predetermined manufacturing section, so that the respective manufactured object can be identified by identifying the corresponding data collecting device.
The first and the second manufacturing sections can be chosen in accordance with the respective requirements. However, it is practical if the first manufacturing section is, viewed in the moving direction of the manufactured object through the manufacturing sections, located in one of the first manufacturing sections, with the second manufacturing section being located in one of the last manufacturing sections. For example, if the large-scale production of automobiles comprises the manufacturing sections press, body structure, paint shop, various preassembly sections, various assembly sections, quality assurance and final inspection, the first manufacturing section may be the preassembly and the second manufacturing section may be the final inspection. In this case, the data collecting device is assigned to the automobile after departure from the paint shop, with this allocation being maintained up to the final inspection.
Another embodiment contains means which determine the respectively instantaneous position of the respective data collecting device and the respective manufactured object in the large-scale production, with data that represent the respectively determined instantaneous position of the respective data collecting device and the respective manufactured object being at least occasionally transmitted to the central device. Due to this measure, a certain manufactured object can be located within the manufacturing sections at any time from the central device.
One additional development of the aforementioned embodiment proposes that the means which determine the respectively instantaneous position of the respective data collecting device and the respective manufactured object contain several reception devices that are stationarily arranged and spaced apart from one another within the region of the manufacturing sections. In this case, each data collecting device at least occasionally transmits a log-on signal that is received by different stationary reception devices in a chronologically successive fashion during the passage through the manufacturing sections, namely in such a way that the instantaneous position of the respective data collecting device and the respective manufacturing object can be determined by ascertaining which of the stationary reception devices currently receives the log-on signal from the respective data collecting device. In this embodiment, each data collecting device notifies the stationary reception devices of its arrival similar to a xe2x80x9croaming method.xe2x80x9d This makes it possible to easily and reliably determine the instantaneous location of a manufactured object with the assigned data collecting device.
According to another additional development, data which contain a code for a identifying the manufactured object and/or the data collecting device, from which the data originate, are transmitted together with the manufacturing-related data or separately therefrom.
According to another additional development, the manufacturing-related data contain a code for identifying the manufacturing section, in which these data are input, and/or a code for identifying a worker who is active in this manufacturing section and/or a code for identifying a group of workers who are active in this manufacturing section. Due to this measure, it is possible to determine which worker or which group of workers has installed and, if applicable, registered a complaint regarding a component or a group of components.
The manufacturing-related data can be transmitted from the data collecting device to the central device or each central device by wire or by wireless means, in particular, via radio or infrared radiation. With wired transmission, electric transmission lines may, for example, be provided on an assembly line, with the data collecting device being connected to the electric transmission lines by means of, for example, a plug connection. A wireless transmission, in particular, via radio, is simple, uncomplicated and not susceptible to interference.
It is practical that the manufacturing-related data be transmitted during the passage through the manufacturing sections. This means that the data transmission takes place simultaneously with the passage through the manufacturing sections. According to another additional development of the method according to the invention, the data are transmitted to the central device immediately after their input into the data collecting device. This means that the data are available in the central device shortly after they are collected.
According to one embodiment of the invention, the data that belong to a manufactured object and/or a manufacturing section are transmitted to the central device in a chronological correlation to the departure of the manufactured object from this manufacturing section, in particular, during or shortly after the departure from the manufacturing section. Due to this measure, a data transmission always takes place when a manufacturing section is completed. This simplifies the planning of subsequent work, in particular, if several subsequent work procedures that are correlated to one another and pertain to the same manufacturing section need to be carried out.
According to another embodiment, the data are transmitted to the central device upon request. In this embodiment, the central device determines the time, at which the data transmission takes place.
According to another embodiment, a holding arrangement for the data collecting device is provided on the manufactured object or in its immediate vicinity, with the transmission of data being initiated by depositing the respective data collecting device in the assigned holding arrangement. This holding arrangement may be realized similar to a docking station, with the data transmission respectively being initiated once the data collecting device is deposited into the docking station.
The manufacturing-related data may, for example, consist of data that contain arbitrary information on the status of the manufactured object and/or components used. For example, the data may contain information which indicates that a certain component or a certain group of components was installed in a functional and flawless condition. However, it is preferred that the manufacturing-related data consists of data that represent the presence of a defect on a component and/or the type and/or the location of a defect on the component and/or the location of a defect on the manufactured object and/or a missing component. In this embodiment, manufacturing-related data are only input into the data collecting device and transmitted if a defect has occurred. If no defect has occurred, no data are input and transmitted. This reduces the quantity of data to be input and transmitted and consequently saves time.
The data collecting device may be realized arbitrarily in accordance with the respective requirements. For example, the data can be input into the data collecting device by means of a keyboard or a keypad.
According to one particularly practical additional development, the data are input into the data collecting device by means of a touchscreen. This simplifies the data input and saves time because it is, in principle, no longer necessary to use a keyboard or a keypad.
According to another additional development, the data can be input into the data collecting device by means of a scanner for scanning a barcode. This type of data input is particularly fast and uncomplicated; however, this method requires that the worker who inputs the data is provided with a corresponding barcode for scanning.
It is practical that the data collecting device contain a display device for monitoring and/or controlling the data input. Due to this measure, it is possible to visually control the data input such that the risk of input errors is reduced.
In another advantageous additional development, at least one input menu is illustrated on the display device or the touchscreen, with the data input being realized by selecting one element or several elements from the input menu. This means that the data input takes place in a menu-controlled fashion in this embodiment, i.e., the input is simplified and the time required for the input is reduced.
In one particularly advantageous additional development of the previously described embodiments, an input menu is illustrated on the display device or the touchscreen in each manufacturing section, namely in accordance with the respective components used in this manufacturing section. In this case, only the components which are required in this particular manufacturing section are displayed in the respective input menu. This additionally simplifies the data input and reduces the risk of input errors.
It would, in principle, suffice to plan any required subsequent work based on the data available in the central device. However, a particularly advantageous additional development proposes that data which originate from different manufactured objects are evaluated in the central device, and that defect data are generated after the evaluation which contains information on the presence of defects on components and/or groups of components used in the large-scale production, with the defect data being transmitted by the central device to the manufacturing sections, in which the respective component and/or groups of components are manufactured and/or prepared and/or made available. Due to this measure, a return message is immediately transmitted to the *j sections, from which defective components or groups of components originate. Corresponding measures for eliminating and avoiding the respective defect can be taken in these sections. The evaluation may take place arbitrarily in accordance with the respective requirements. For example, a statistic evaluation may be carried out which always generates a return message if a certain quantity of defects has occurred or if defects have occurred in a certain a sequence.
According to one embodiment, an assembly line is used in the large-scale production, with the different manufacturing sections being formed by the regions of the assembly line which lie successively viewed in the moving direction of the manufactured objects.
It is preferred that the data collecting devices consist of computer-assisted data collecting devices.